Center UIPickerView Text

A little easier now in iOS 6... There's a new method you can implement to return an attributed string... And you can define alignment in attributed strings.

- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component {
    NSString *text = [NSString stringWithFormat:@"R%d C%d", row, component];
    NSMutableAttributedString *as = [[NSMutableAttributedString alloc] initWithString:text];
    NSMutableParagraphStyle *mutParaStyle=[[NSMutableParagraphStyle alloc] init];
    mutParaStyle.alignment = NSTextAlignmentCenter;
    [as addAttribute:NSParagraphStyleAttributeName value:mutParaStyle range:NSMakeRange(0,[text length])];
    return as;
}

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 37)];
    label.text = [NSString stringWithFormat:@"something here"];
    label.textAlignment = NSTextAlignmentCenter; //Changed to NS as UI is deprecated.
    label.backgroundColor = [UIColor clearColor];
    [label autorelease];
    return label;
}

or something like this.

You can implement this delegate method, which returns a CGFloat

- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component

This is called on the picker view to determine row width.

Below one also working fine -

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
    UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
    lbl.text = [reservePickerArray objectAtIndex:row];
    lbl.adjustsFontSizeToFitWidth = YES;
    lbl.textAlignment=UITextAlignmentCenter;
    lbl.font=[UIFont systemFontOfSize:20];
    return lbl;
}

Cheers!!